[Show abstract][Hide abstract] ABSTRACT: Both of gp91(phox) (an isoform of nicotinamide adenine dinucleotide phosphate reduced oxidases) and Src (a non-receptor protein tyrosine kinase) are abundantly expressed in the brain and play a prominent role in mediating ischemic alteration in neurons. The inhibitory strategy of them is believed to be the promising treatment of stroke. The present study was designed to investigate the effect of equol (0.625-2.5 mg•kg(-1), i.g. for 3 days), a predominant active metabolite of daidzein, on neuroprotection against cerebral ischemia/reperfusion injury in rats and the underlying mechanisms. We found that equol decreased the mortality, neurological deficit, brain histological damage, infarct volume, serum lactate dehydrogenase activity and malondialdehyde content in a dose-dependent manner in rats with 2-h middle cerebral artery occlusion, followed by 22-h reperfusion. Western blot analysis revealed that protein levels of gp91(phox) and phosphorylated Src-Tyr416 (p-Src) in ischemic cerebral cortex were increased in rats treated with vehicle, which was reversed in animals treated with equol. In rat pheochromocytoma cell line (PC12) with hypoxia/reoxygenation injury, silencing of gp91(phox) with specific siRNA did not affect the increase of p-Src level by hypoxia/reoxygenation injury and the inhibition of p-Src level by equol, while silencing of Src suppressed the upregulation of gp91(phox) by hypoxia/reoxygenation injury and enhanced the inhibitory effect of equol on gp91(phox) expression. These results demonstrate that equol confers a neuroprotection in rats via inhibiting the activation of Src and upregulation of gp91(phox) induced by focal cerebral ischemia/reperfusion, and Src may play a partial role in regulating gp91(phox) expression of neurons.
Current Neurovascular Research 09/2014; 11(4). DOI:10.2174/1567202611666140908094517 · 2.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The present study was designed to investigate the effect of metformin on the impairment of intermediate-conductance and small-conductance Ca(2+)-activated potassium channels (IKCa and SKCa)-mediated relaxation in diabetes and the underlying mechanism. The endothelial vasodilatation function of mesenteric arteries was assessed with the use of wire myography. Expression levels of IKCa and SKCa and phosphorylated Thr(172) of AMP-activated protein kinase (AMPK) were measured by using Western blot technology. The channel activity was observed by using whole-cell patch voltage-clamp. Reactive oxygen species (ROS) were measured by using dihydroethidium and 2', 7'-dichlorofluorescein diacetate. Metformin restored the impairment of IKCa and SKCa-mediated vasodilatation in mesenteric arteries from streptozotocin-induced type 2 diabetic rats and that from normal rats incubated with advanced glycation end products (AGEs) for 3 h. In cultured human umbilical vein endothelial cells (HUVECs), 1 μM metformin reversed AGEs-induced increase of ROS and attenuated AGEs- and H2O2- induced downregulation of IKCa and SKCa after long term incubation (>24 h). While short-term treatment (3 h) with 1 μM metformin reversed the decrease of IKCa and SKCa currents induced by AGEs-incubation for 3 h without changing the channel expression and the AMPK activation in HUVECs. These results demonstrate for the first time that metformin restored IKCa and SKCa-mediated vasodilatation impaired by AGEs in rat mesenteric artery, in which the upregulation of channel activity and protein expression is likely involved.
[Show abstract][Hide abstract] ABSTRACT: Cardiac progenitor cells play an important role in cardiac repair and regeneration; however, their cellular biology and electrophysiology are not understood. The present study characterizes the functional ion channels in human cardiac c-kit(+) progenitor cells using whole-cell patch voltage-clamp, RT-PCR, and Western blots. We found that several ionic currents were present in human cardiac c-kit(+) progenitor cells, including a large-conductance Ca(2+)-activated K(+) current (BKCa) in 86 % of cells, an inwardly rectifying K(+) current (I Kir) in 84 % of cells, a transient outward K(+) current (I to) in 47 % of cells, a voltage-gated tetrodotoxin-sensitive Na(+) current (I Na,TTX) in 61 % of cells. Molecular identities of these ionic currents were determined with RT-PCR and Western-blot analysis. KCa.1.1 (for BKCa), Kir2.1 (for I Kir), Kv4.2 and Kv4.3 (for I to), Nav1.3 and Nav1.6 (for I Na.TTX) were abundantly expressed in human cardiac c-kit(+) progenitor cells, which do not resemble cardiomyocytes at all. These results demonstrate for the first time that four types of ionic currents including BKCa, I to, I Kir, and I Na.TTX, are heterogeneously present in human cardiac c-kit(+) cells, which may be involved in regulating cellular physiology.
Archiv für Kreislaufforschung 05/2014; 109(3):407. DOI:10.1007/s00395-014-0407-z · 5.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cellular excitability is an important physiological factor in maintaining normal cardiac activity. The present study was designed to investigate the ionic mechanism underlying different excitability in atrial and ventricular myocytes of guinea pig heart using a whole-cell patch configuration. We found that excitability is lower in ventricular myocytes than that in atrial myocytes. Although the density of voltage-gated fast Na(+) current (INa) was lower in ventricular myocytes, it would not correlate to the lower excitability since its availability was greater than that in atrial myocytes around threshold potential. Classical inward rectifier K(+) current (IK1) was greater in ventricular myocytes than that in atrial myocytes, which might contribute in part to the lower excitability. In addition, the transient outward K(+) current with inward rectification (Itoir) elicited by depolarization was greater in ventricular myocytes than that in atrial myocytes and might contribute to the lower excitability. In ventricular myocytes, Ba(2+) at 5 µmol/L significantly inhibited Itoir, enhanced excitability, and shifted the threshold potential of INa activation to more negative, and the effect was independent of affecting INa. Our results demonstrate the novel information that in addition to classical IK1, Itoir plays a major role in determining the distinctive excitability in guinea pig atrial and ventricular myocytes and maintaining cardiac excitability. More effort is required to investigate whether increase of Itoir would be protective via reducing excitability.
Sheng li xue bao: [Acta physiologica Sinica] 02/2014; 66(1):85-95.
[Show abstract][Hide abstract] ABSTRACT: To investigate the changes in aorta morphology and Ca(2+)-activated K(+) (KCa) channel expression in the diabetic rats.
A diabetic rat model was established by a single intraperitoneal injection of streptozotocin (30 mg/kg) after a modified high fat and glucose diet for 8 weeks. Pathological changes in the aorta were observed with HE staining, elastic fiber staining, Masson's trichrome staining and immunohistochemistry. Both the mRNA and protein levels of KCa channels in the aorta were measured by RT-PCR and Western blotting.
Early atherosclerotic changes were observed in the aorta wall of the diabetic rats. The mRNA and protein levels of KCa1.1 channel α- and β-subunits were significantly decreased, while the expression of KCa3.1 channels was obviously enhanced in the middle layer of the aorta in the diabetic rats.
KCa channel switching in smooth muscles may play a role in the development of atherosclerosis in diabetic rats.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 02/2014; 34(2):188-92.
[Show abstract][Hide abstract] ABSTRACT: Cholesterol is one of the major lipid components of the plasma membrane in mammalian cells and is involved in the regulation of a number of ion channels. The present study investigates how large conductance Ca(2+)-activated K(+) (BK) channels are regulated by membrane cholesterol in BK-HEK 293 cells expressing both the α-subunit hKCa1.1 and the auxiliary β1-subunit or in hKCa1.1-HEK 293 cells expressing only the α-subunit hKCa1.1 using approaches of electrophysiology, molecular biology, and immunocytochemistry. Membrane cholesterol was depleted in these cells with methyl-β-cyclodextrin (MβCD), and enriched with cholesterol-saturated MβCD (MβCD-cholesterol) or low-density lipoprotein (LDL). We found that BK current density was decreased by cholesterol enrichment in BK-HEK 293 cells, with a reduced expression of KCa1.1 protein, but not the β1-subunit protein. This effect was fully countered by the proteasome inhibitor lactacystin or the lysosome function inhibitor bafilomycin A1. Interestingly, in hKCa1.1-HEK 293 cells, the current density was not affected by cholesterol enrichment, but directly decreased by MβCD, suggesting that the down-regulation of BK channels by cholesterol depends on the auxiliary β1-subunit. The reduced KCa1.1 channel protein expression was also observed in cultured human coronary artery smooth muscle cells with cholesterol enrichment using MβCD-cholesterol or LDL. These results demonstrate the novel information that cholesterol down-regulates BK channels by reducing KCa1.1 protein expression via increasing the channel protein degradation, and the effect is dependent on the auxiliary β1-subunit.
PLoS ONE 11/2013; 8(11):e79952. DOI:10.1371/journal.pone.0079952 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The present study was designed to investigate the role of advanced glycation end products (AGEs) in intermediate-conductance and small-conductance Ca2+-activated potassium channels (KCa3.1 and KCa2.3)-mediated relaxation in rat resistance arteries and the underlying mechanism. The endothelial function of mesenteric arteries was assessed with the use of wire myography. Expression levels of KCa3.1 and KCa2.3 were measured by using Western blot. Reactive oxygen species (ROS) were measured by using dihydroethidium and 2′, 7′-dichlorofluorescein diacetate. KCa3.1 and KCa2.3-mediated vasodilatation responses to acetylcholine and NS309 (opener of KCa3.1 and KCa2.3) were impaired by incubation of the third-order mesenteric arteries from normal rats with AGEs (200 μg ml−1 for 3 h). In cultured human umbilical vein endothelial cells (HUVECs), AGEs increased ROS level and decreased the protein expression of KCa3.1 and KCa2.3. Antioxidant alpha lipoic acid restored the impairment in both vasodilatation function and expression of KCa3.1 and KCa2.3. H2O2 could mimic the effect of AGEs on the protein expression of KCa3.1 and KCa2.3 in cultured HUVECs. These results demonstrate for the first time that AGEs impaired KCa3.1 and KCa2.3-mediated vasodilatation in rat mesenteric arteries via downregulation of both KCa3.1 and KCa2.3, in which the enhanced oxidative stress was involved.
Pflügers Archiv - European Journal of Physiology 07/2013; DOI:10.1007/s00424-013-1324-y · 3.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To investigate the role of oxidative stress in impaired intermediate-conductance Ca(2+)-activated potassium channels (IKCa)- and small-conductance Ca(2+)-activated potassium channels (SKCa)-mediated relaxation in diabetic resistance arteries.
Rat diabetic model was induced by a high fat and high glucose diet and streptozotocin (STZ) injection. Endothelial function of mesenteric arteries was assessed with the use of wire myography. The expression levels of IKCa and SKCa in cultured human umbilical vein endothelial cells (HUVECs) treated with H2O2 and/or antioxidant alpha lipoic acid (ALA) were measured using Western blotting.
IKCa- and SKCa-mediated vasodilatation in response to acetylcholine was impaired in the third-order mesenteric arterioles of diabetic rats. In cultured HUVECs, H2O2 significantly decreased the protein expression of IKCa and SKCa. ALA alleviated the impairment of both vasodilatation function of the mesenteric arterioles ex vivo and enhanced the expression of IKCa and SKCa challenged with H2O2 in cultured HUVECs.
Our data demonstrated for the first time that impaired IKCa- and SKCa-mediated vasodilatation in diabetes was induced, at least in part, by oxidative stress via down-regulation of IKCa and SKCa channels.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 07/2013; 33(7):939-944.
[Show abstract][Hide abstract] ABSTRACT: The proliferation of cardiac fibroblasts is implicated in the pathogenesis of myocardial remodeling and fibrosis. Intermediate-conductance calcium-activated K(+) channels (KCa3.1 channels) have important roles in cell proliferation. However, it is unknown whether angiotensin II (Ang II), a potent profibrotic molecule, would regulate KCa3.1 channels in cardiac fibroblasts and participate in cell proliferation. In the present study, we investigated whether KCa3.1 channels were regulated by Ang II, and how the channel activity mediated cell proliferation in cultured adult rat cardiac fibroblasts using electrophysiology and biochemical approaches. It was found that mRNA, protein, and current density of KCa3.1 channels were greatly enhanced in cultured cardiac fibroblasts treated with 1μM Ang II, and the effects were countered by the angiotensin type 1 receptor (AT1R) blocker losartan, the p38-MAPK inhibitor SB203580, the ERK1/2 inhibitor PD98059, and the PI3K/Akt inhibitor LY294002. Ang II stimulated cell proliferation and the effect was antagonized by the KCa3.1 blocker TRAM-34 and siRNA targeting KCa3.1. In addition, Ang II-induced increase of KCa3.1 expression was attenuated by transfection of activator protein-1 (AP-1) decoy oligodeoxynucleotides. These results demonstrate for the first time that Ang II stimulates cell proliferation mediated by upregulating KCa3.1 channels via interacting with the AT1R and activating AP-1 complex through ERK1/2, p38-MAPK and PI3K/Akt signaling pathways in cultured adult rat cardiac fibroblasts.
[Show abstract][Hide abstract] ABSTRACT: BiOBr photocatalyst was prepared by a facile hydrolysis method, and then characterized by X-ray diffraction, scanning electron microscopy, N2 sorption isotherms, and diffuse reflectance spectroscopy. The as-prepared BiOBr photocatalyst was found to be a tetragonal crystal structure, homogeneous particles of fine ferrite plates, surface area of 32.19 m2/g, and band gap of 2.92 eV. The photocatalytic property and mechanism of BiOBr were investigated by the degradation of methylene orange (MO) in aqueous solution under xenon lamp irradiation. The results indicated that the optimum amount of BiOBr powder was 0.8 g/L for MO degradation under xenon lamp irradiation, and its catalytic performance was as good as that of P25-TiO2. The mechanism study showed that photogenerated holes and •OH played important roles in photocatalytic degradation. The photocatalytic degradation results of humic acids, methylene blue, and MO in aqueous solution further verified the high catalytic activity and non-selectivity of BiOBr.
Journal of Solid State Chemistry 03/2013; 199:224–229. DOI:10.1016/j.jssc.2012.12.031 · 2.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The mechanisms underlying the involvement of advanced glycation endproducts (AGEs) in diabetic atherosclerosis are not fully understood. The present study was designed to investigate whether intermediate-conductance Ca(2+)-activated K(+) channels (K(Ca)3.1 channels) are involved in migration and proliferation induced by AGEs in cultured rat vascular smooth muscle cells (VSMCs) using approaches of whole-cell patch voltage-clamp, cell proliferation and migration assay, and western blot analysis. It was found that the current density and protein level of K(Ca)3.1 channels were enhanced in cells incubated with AGE-BSA (bovine serum albumin), and the effects were reversed by co-incubation of AGE-BSA with anti-RAGE (anti-receptors of AGEs) antibody. The ERK1/2 inhibitors PD98059 and U0126, the P38-MAPK inhibitors SB203580 and SB202190, or the PI3K inhibitors LY294002 and wortmannin countered the K(Ca)3.1 channel expression by AGE-BSA. In addition, AGE-BAS increased cell migration and proliferation, and the effects were fully reversed with anti-RAGE antibody, the K(Ca)3.1 channel blocker TRAM-34, or K(Ca)3.1 small interfering RNA. These results demonstrate for the first time that AGEs-induced increase of migration and proliferation is related to the upregulation of K(Ca)3.1 channels in rat VMSCs, and the intracellular signals ERK1/2, P38-MAPK and PI3K are involved in the regulation of K(Ca)3.1 channel expression.Laboratory Investigation advance online publication, 19 November 2012; doi:10.1038/labinvest.2012.163.
[Show abstract][Hide abstract] ABSTRACT: A series of zinc titanate nanoparticles was successfully synthesized using a simple sol–gel technique. The composites were characterized by thermogravimetric and differential thermal analysis (TG-DTA), X-ray diffraction (XRD) patterns, scanning electron microscope (SEM), X-ray photoelectron spectra (XPS) and UV–vis diffuse reflectance spectra (UV–vis). The photocatalytic activity of samples was investigated by degradation of humic acid (HA) in water under xenon lamp. The sample calcined at 800 °C was found to exhibit much higher photocatalytic activity than the other samples. The investigation of photocatalytic mechanism indicates that the holes (h+) and OH radicals may be the major reactive species for the degradation of HA. Meanwhile, the processing parameters such as the light source and the dosage of catalysts play an important role in tuning the photocatalytic activity. The enhancement of photocatalytic activity for the zinc titanate nanoparticles calcined at 800 °C may be attributed to the higher redox ability, coordination of Ti ions and smaller particle size.
Ceramics International 07/2012; 38(5):4173–4180. DOI:10.1016/j.ceramint.2012.01.078 · 2.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A novel photocatalyst, bismuth oxychloride (BiOCl) micro-nano particles with a fine ferrite plate structure, was prepared by a low-cost, simple hydrolytic method. The as-prepared BiOCl was characterized by scanning electron microscopy (SEM), thermogravimetric analysis-differential thermal analysis (TGA-DTA), X-ray diffraction (XRD), and UV-vis diffuse reflectance spectra (DRS). The effects of preparation conditions such as sodium dodecyl benzene sulfonate (SDBS) dispersant, HCl concentration, and heat treatment temperature on BiOCl performances were investigated. Moreover, its photocatalytic activity was evaluated on the degradation of methylene orange (MO) and was compared with that of TiO2 (P25). The experimental results confirmed that BiOCl micro-nano particles prepared with SDBS, the HCl concentration of 1.5 mol/L, and the heat treatment temperature of 80°C exhibited the best performance for the photodegradation of MO solution, and they showed good stability and better photocatalytic activity than P25 photocatalyst.
International Journal of Minerals Metallurgy and Materials 05/2012; 19(5). DOI:10.1007/s12613-012-0581-7 · 0.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The BiOCl powders prepared by the hydrolysis method were investigated with the X-ray diffractometry (XRD), scanning electron microscopy (SEM) and differential thermal analysis (TG-DTA). The results show that the powders are of the tetragonal primitive crystal structure, composed of homogeneous particles of fine ferrite plates, and stable in the temperature range of 40-600 °C. In addition, the photocatalytic activity of BiOCl powders was evaluated by methyl orange (MO) in aqueous solution illuminated by xenon-lamp, and the effect of the BiOCl amount on the photocatalytic activity was investigated. Moreover, the photocatalytic properties of BiOCl and TiO2-P25 were also compared. The results show that the favorite amount of BiOCl powders is 1.0 g/L for the MO degradationand the photocatalytic activity of the BiOCl catalyst is comparable to the TiO2-P25 catalyst under the same experiment condition.
Transactions of Nonferrous Metals Society of China 10/2011; 21(10):2254-2258. DOI:10.1016/S1003-6326(11)61004-2 · 1.00 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The detailed molecular mechanisms underlying pathogenesis of various vascular diseases such as atherosclerosis are not fully understood in type-2 diabetes. The present study was designed to investigate whether insulin regulates K(Ca)3.1 channels and participates in vasculopathy in type-2 diabetes. A rat model with experimental insulin-resistant type-2 diabetes was used for detecting pathological changes in the aorta wall, and cultured vascular smooth muscle cells (VSMCs) were employed to investigate the regulation of K(Ca)3.1 channels by insulin and roles of K(Ca)3.1 channels in cell migration and proliferation using molecular biology and electrophysiology. Early pathological changes were observed and expression of K(Ca)3.1 channels increased in the aorta wall of the type 2 diabetic rats. K(Ca)3.1 channel mRNA, protein levels and current density were greatly enhanced in cultured VSMCs treated with insulin, and the effects were countered in the cells treated with the ERK1/2 inhibitor PD98059, but not the p38-MAPK inhibitor SB203580. In addition, insulin stimulated cell migration and proliferation in cultured VSMCs, and the effects were fully reversed in the cells treated with the K(Ca)3.1 blocker TRAM-34 or PD98059, but not SB203580. These results demonstrate the novel information that insulin increases expression of K(Ca)3.1 channels by stimulating ERK1/2 phosphorylation thereby promoting migration and proliferation of VSMCs, which likely play at least a partial role in the development of vasculopathy in type-2 diabetes.
Journal of Molecular and Cellular Cardiology 04/2011; 51(1):51-7. DOI:10.1016/j.yjmcc.2011.03.014 · 5.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Daidzein, a phytoestrogen, has been reported to produce vasodilation via inhibition of Ca(2+) inflow. However, the involvement of large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels in the effect of daidzein is debated. Therefore, the present study was designed to investigate the effect of daidzein on the rat cerebral basilar artery and the underlying molecular mechanisms. Isolated cerebral basilar artery rings and single vascular smooth muscle cells (VSMCs) were used for vascular reactivity and electrophysiology measurements, to investigate the effect of daidzein on BK(Ca) channels in cerebral basilar artery smooth muscle. In addition, the human BK(Ca) channel alpha-subunit gene (hslo) was transfected into HEK293 cells, to directly assess whether daidzein activates BK(Ca) channels. The results showed that daidzein produced a concentration-dependent but endothelium-independent relaxation in rat cerebral basilar arteries. Paxilline, a selective BK(Ca) channel blocker, significantly inhibited the daidzein-induced vasodilation, whereas NS1619, a selective BK(Ca) channel opener, enhanced the vasodilation. In the whole-cell configuration, daidzein increased noisy oscillation currents in cerebral basilar artery VSMCs in a concentration-dependent manner, and washout of daidzein or blockade of BK(Ca) channels with paxilline fully reversed the increase. However, daidzein did not substantially affect hSlo currents in HEK293 cells when applied to the outside of the cell membrane. In conclusion, these results indicate that the activation of BK(Ca) channels in VSMCs at least partly contributes to the daidzein-induced vasodilation of the rat cerebral basilar artery. The beta1-subunit of BK(Ca) channels plays a critical role in the activation of BK(Ca) currents by daidzein.
European journal of pharmacology 03/2010; 630(1-3):100-6. DOI:10.1016/j.ejphar.2009.12.032 · 2.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cerebral vascular dysfunction and associated vascular complications often develop over time in type-2 diabetes, but the underlying mechanisms are not wholly understood. The aim of the present study was to investigate whether large-conductance Ca(2+)-activated K(+) (BKCa) channels in cerebral artery smooth muscle cells (CASMCs) were impaired in experimental model of type-2 diabetes, and the changes could account for cerebral vascular complication in type-2 diabetes. Sprague-Dawley rats were fed with high fat and glucose diet for 8 weeks and then injected with streptozotocin (STZ/30 mg/kg i.p.). Three months after injection of STZ, the alterations of BKCa channels were assessed by using multi-myograph system, patch-clamp, RT-PCR and Western blot. Our results show that the model is characterized by insulin resistance, hyperglycaemia, hyperlipidemia and moderate hypertension, which resembles the clinical manifestation of patients with typre-2 diabetes. Inhibition of BKCa channels with 1 mM tetraethylammonium (TEA) or 1 microM paxilline (PAX) causes smaller constriction in type-2 diabetic cerebral basilar arteries than control arteries. The contractile efficacy of 5-Hydroxytryptamine (5-HT) is substantially reduced by TEA or PAX pretreatment in control > diabetic basilar artery rings. The response to 5-HT in diabetic basilar artery rings is higher than that of control artery rings after activation of BKCa channels with NS1619. The whole-cell K(+) currents are significantly decreased in type-2 diabetic CASMCs compared to control, and the sensitivity of BKCa channels to voltage, the specific inhibitor and opener are all diminished in diabetic CASMCs. The expression of BKCa channel beta1, but not alpha-subunits is markedly reduced at both of mRNA and protein levels in endothelial-denudated cerebral arteries. In conclusion, type-2 diabetes downregulates BKCa channel beta1-subunits in CASMCs, resulting in reduced activity of BKCa channel, increased vascular tone and blood pressure, thereby contributing to cerebral vascular complication in type-2 diabetes.
Current neurovascular research 03/2010; 7(2):75-84. DOI:10.2174/156720210791184925 · 2.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Two types of Sb-doped SnO2 films on titanium substrate were prepared by the combination of electro-deposition and dip-coating (Ti/SnO2-Sb2O4/SnO2-Sb2O4) and single dip-coating (Ti/SnO2-Sb2O4), respectively. The surface morphology and crystalline structure of both film electrodes were characterized using X-ray diffractometry(XRD) and scanning electron microscopy(SEM). XRD spectra indicate that the rutile SnO2 forms in two films and a TiO2 crystallite exists only in Ti/SnO2-Sb2O4 electrode. SEM images show that the surface morphology of two films is typically cracked-mud structure. The photooxidation experiment was proceeded to further confirm the two electrode activity. The results show that the photoelectrocatalytic degradation efficiency of Ti/SnO2-Sb2O4 electrode with sub-layer is higher than that of simple Ti/SnO2-Sb2O4 electrode using phenol as a model organic pollutant. The Ti/SnO2-Sb2O4/SnO2-Sb2O4 photoanode has a better photoelectrochemical performance than Ti/SnO2-Sb2O4 photoanode for the removal of organic pollutants from water.
Transactions of Nonferrous Metals Society of China 06/2009; 19(3):778-783. DOI:10.1016/S1003-6326(08)60349-0 · 1.00 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Four and a half of LIM-only protein 2 (FHL2) is an adaptor protein that can interact with many transcription factors and thus
plays a variety of biological functions. Previous studies by our group have demonstrated that suppression of FHL2 was capable
of inducing tumor cell differentiation, and inhibiting the growth of experimental gastric and colon cancers. Therefore, FHL2
appears to function as an oncogene. In order to further explore the mechanisms of how FHL2 is involved in tumorigenesis, we
attempted to test whether FHL2 has any direct association with nuclear factor (NF-κB), the most important transcription factor
involved in apoptosis, inflammation, and carcinogenesis. Using an Yeast Two Hybrid (Y2H) screening system, we have shown that
FHL2 may have an interaction with NF-κBIα, the coding gene for IκBα which is the most potent endogenous inhibitor for NF-κB
activation. However, subsequent studies using co-immunoprecipitation and co-localization failed to confirm the Y2H finding.
Down-regulation of FHL2 by FHL2-siRNA down-regulated the expression of NF-κB p65. We therefore concluded that under the physiological
condition, FHL2 may activate NF-κB pathway, even though such an activation may not be mediated by a direct binding of FHL2
to NF-κB inhibitor protein IκB.